Develop Reference

Why does the border stop rendering its minus margin while resizing the grid

I've used a border with negativ margin to mark a grid row. But I get a strange behaviour while resizing the window. Cutting the second column of the row makes the margin of the border disappear:
Of course this is a small example, in the main application I'm using a grid splitter, but the bahaviour stays the same. Is it possible to fix this somehow or is it a WPF bug?
MainWindow.xaml:
<Window x:Class="TestHighlightBorder.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:TestHighlightBorder"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Grid Margin="100,0,0,0" >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="200" />
<ColumnDefinition Width="10" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="40" />
</Grid.RowDefinitions>
<Border Background="DarkRed" Opacity="0.3" Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="3" Margin="-80,0,0,0" Panel.ZIndex="1" />
<TextBlock Text="column 0" Background="LightBlue" Grid.Row="0" Grid.Column="0" />
<TextBlock Text="column 2" Background="LightGreen" Grid.Row="0" Grid.Column="2" />
</Grid>
ps:
This is how the main application looks like. It's some sort of a propertygrid. The amount of the negativ margin depends on the level of nested objects.

I tried your example and it happens just as you said: column 2 gone, margin gone.
This seems to happen whenever the grid can't be displayed completely.
If, for example you set the third column definition to 200, the margin disappears as soon as column 2 isn't shown in it's entirety. Same thing happens when you resize the window from the bottom.
If you put the existing grid in another container (Grid, StackPanel, etc.) and set the MinWidth to something at least the size of the width of the columns + margin (in your example 310), this doesn't happen.
Like so:
<StackPanel MinWidth="310">
<Grid Margin="100,0,0,0" >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="200" />
<ColumnDefinition Width="10" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="40" />
</Grid.RowDefinitions>
<Border Background="DarkRed" Opacity="0.3" Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="3" Margin="-80,0,0,0" Panel.ZIndex="1" />
<TextBlock Text="column 0" Background="LightBlue" Grid.Row="0" Grid.Column="0" />
<TextBlock Text="column 2" Background="LightGreen" Grid.Row="0" Grid.Column="2" />
</Grid>
</StackPanel>

Instead of adding a 100 left-margin to the grid, you could just fix a column at the beginning with the width of 100, set the column-span of the border to 4, replace the negative margin with 20 positive left-margin (100-80=20), and add 1 to the value of Grid.Column for each of your controls. So the final approach would look like that:
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="100" />
<ColumnDefinition Width="200" />
<ColumnDefinition Width="10" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="40" />
</Grid.RowDefinitions>
<Border Background="DarkRed" Opacity="0.3" Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="4" Margin="20,0,0,0" Panel.ZIndex="1" />
<TextBlock Text="column 0" Background="LightBlue" Grid.Row="0" Grid.Column="1" />
<TextBlock Text="column 2" Background="LightGreen" Grid.Row="0" Grid.Column="3" />
</Grid>

WPF Control To Imitate HTML Console

I'm guessing there's not a control that does this automatically, but I'm looking for a way to implement something like this in a wpf application. Here's what I'd like for it to do.
Take commands into it like a cli (This could be a separate text box
if necessary).
Output normal text and support HTML colors.
History that scrolls up as your cursor moves down after each command.
HTML formatted divs, tables, and text formatting (no js needed)
Small images no larger than 100x100
How do I start making this? Do I start with a StackPanel?

I Added two rows with four colomns in a grid panel
In the first row fourth colomn add a stackpanel for normal text
Out side the grid you also add image as well as inside
That I include for your reference
The grid is nested in the scroll
<Window x:Class="Wpftest.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:Wpftest"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<ScrollViewer Margin="5" CanContentScroll="False"
HorizontalScrollBarVisibility="Auto">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<Image Source="Augustus.jpg" Height="100" Margin="10"/>
<Label Grid.Column="1" Content="Augustus - 63BC - 14AD" />
<Image Grid.Column="2" Source="Tiberius.jpg" Height="100" Margin="10"/>
<Label Grid.Column="3" Content="Tiberius - 42BC - 37AD"/>
<StackPanel Grid.Row="0" Grid.Column="4">
<TextBlock FontSize="15">Your Normal text</TextBlock>
</StackPanel>
<Button Grid.Row="1" Content="Learn"
HorizontalAlignment="Center" VerticalAlignment="Center"
Padding="10,5"/>
<Button Grid.Row="1" Grid.Column="2" Content="Learn"
HorizontalAlignment="Center" VerticalAlignment="Center"
Padding="10,5"/>
<Button Grid.Row="1" Grid.Column="4" Content="Inputs"
HorizontalAlignment="Center" VerticalAlignment="Center"
Padding="10,5"/>
</Grid>
</ScrollViewer>
</Window>

UWP XAML: Filling the screen with 2 elements, one Viewbox

I have a grid with two elements, a scaling Viewbox and a Textblock. I want to have the Viewbox take only the space it needs, but also only the space it can get.
Images explain it much better, the desired image first:
However, when I resize my application to be wider, the Viewbox starts to overtake the Textblock below it:
Here's a dumbed down version of my XAML:
<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}" x:Name="MainGrid" Margin="0" UseLayoutRounding="False">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="0" />
</Grid.ColumnDefinitions>
<Viewbox Stretch="Uniform" VerticalAlignment="Top" HorizontalAlignment="Left" Grid.Row="0" x:Name="Zulrah">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition />
<ColumnDefinition />
</Grid.ColumnDefinitions>
<Rectangle Grid.Column="0" Fill="Blue" Width="150" Height="250" VerticalAlignment="Stretch" HorizontalAlignment="Stretch"/>
<Rectangle Grid.Column="1" Fill="Red" Width="150" Height="250" VerticalAlignment="Stretch" HorizontalAlignment="Stretch"/>
</Grid>
</Viewbox>
<TextBlock Grid.Row="1" x:Name="TextOutput" MinHeight="100" MinWidth="100">
Hello world!
<LineBreak />
Life's good
</TextBlock>
</Grid>
You can more or less ignore the second column (with Width="0"), it's used for when the application becomes wide-screen (or landscape). It has the same issue:
In short: I want the TextBlock to obey it's MinHeight="100", while still maximizing the space the Viewbox uses.
PS: Please note that some settings make the Viewbox scale to a larger size than actually fits on the screen, this is not desireable!
Edit: Remarkably, setting a MinHeight="100" on the second row has no effect...

Since you are using ThemeResource in your code, I think you are developing an UWP app as there is no ThemeResource in WPF. If so, please remove WPF in your title and tags as they are two different frameworks. Mixed use of UWP and WPF may cause confusion.
For UWP apps, in Grid, while setting row's height to Auto, the row will size to fit its content. After the Auto rows are calculated, the row which height is set to * will get part of the remaining height.
According to your description, you want the TextBlock to obey it's MinHeight and the Viewbox gets part of the remaining height. So you can change the RowDefinitions like following:
<Grid.RowDefinitions>
<RowDefinition Height="*" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
And to make the Viewbox fill the remaining area, we can set VerticalAlignment and HorizontalAlignment to Stretch. Besides this, you may also need to set Stretch property to Fill to make the content in Viewbox resize to fill the destination dimensions.
The complete XAML code may like following:
<Grid x:Name="MainGrid"
Margin="0"
Background="{ThemeResource ApplicationPageBackgroundThemeBrush}"
UseLayoutRounding="False">
<Grid.RowDefinitions>
<RowDefinition Height="*" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="0" />
</Grid.ColumnDefinitions>
<Viewbox x:Name="Zulrah"
Grid.Row="0"
AllowDrop="True"
Stretch="Fill">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition />
<ColumnDefinition />
</Grid.ColumnDefinitions>
<Rectangle Grid.Column="0"
Width="150"
Height="250"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
Fill="Blue" />
<Rectangle Grid.Column="1"
Width="150"
Height="250"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
Fill="Red" />
</Grid>
</Viewbox>
<TextBlock x:Name="TextOutput"
Grid.Row="1"
MinWidth="100"
MinHeight="100">
Hello world!
<LineBreak />
Life's good
</TextBlock>
</Grid>

WPF - Expander in Grid - eating space

I have very simple xaml.
<Grid Margin="0,50,0,0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="30*" />
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
<!--<RowDefinition Height="50"/>-->
</Grid.RowDefinitions>
<Expander Header=""
HorizontalAlignment="Left"
VerticalAlignment="Stretch"
ExpandDirection="Right"
IsExpanded="True"
Grid.Column="0"
Grid.Row="0"
Height="Auto"
>
<!-- My List control -->
</Expander>
<TabControl Name="ExecutionTab" Grid.Column="1" Grid.Row="0" HorizontalAlignment="Stretch">
<!-- soem tabs here -->
</TabControl>
</Grid>
Now after collasping expander the left part [row=0,col=0] being shown as empty with space.
What we want is right part [row=0,col=1] should take whole space.
What should be done in this case ?
I have tried HorizontalAlignment="Stretch" to Tab control but not working.
Do I need to add event handler like on collapse and change width of grid.. but it does not seems to good way ?
Can anyone suggest better way ?
Thanks

Using a Grid is not the best way to achieve what you want. You should use a DockPanel instead with LastChildFill = "true". I can't try it now but I would imagine it like this:
<DockPanel LastChildFill="true">
<Expander Header=""
HorizontalAlignment="Left"
VerticalAlignment="Stretch"
ExpandDirection="Right"
IsExpanded="True"
DockPanel.Dock="Left"
Height="Auto"
>
<!-- My List control -->
</Expander>
<TabControl Name="ExecutionTab" HorizontalAlignment="Stretch">
<!-- soem tabs here -->
</TabControl>
</DockPanel>
This should make the tab control always take the entire remaining space.

You can make this work by setting your column definitions to:
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition/>
</Grid.ColumnDefinitions>
The complete code to show this working is below:
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<Expander ExpandDirection="Right" IsExpanded="True">
<TextBlock FontSize="50">Text For Expander</TextBlock>
</Expander>
<TabControl Name="ExecutionTab" Grid.Column="1">
<TabItem Header="Tab 1">
<TextBox FontSize="50" TextWrapping="Wrap">Text for Tab 1</TextBox>
</TabItem>
<TabItem Header="Tab 2">
<TextBox FontSize="50" TextWrapping="Wrap">Text for Tab 1</TextBox>
</TabItem>
</TabControl>
</Grid>
If you add the xaml above to a window, you should see the following

You will have to make you ColumnDefinition.Width to Auto and if you want fixed width for your TabControl you should give Width to TabControl.
<Grid Margin="0,50,0,0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>

How to make selectable text with 100% height and 100% width of a Grid Cell

I have a Silverlight application and I try to display a generated text into a Cell of my grid. Unfortunately the TextBox does not seem to be able to have a stretching height and stretching width to his parent size. For the moment, I have simply use a ScrollViewer and Set the content but I can't select the text so I still have a problem.
<Grid x:Name="LayoutRoot" Background="White">
<Grid.RowDefinitions>
<RowDefinition Height="*"></RowDefinition>
<RowDefinition Height="50"></RowDefinition>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="500*" />
<ColumnDefinition Width="20"></ColumnDefinition>
<ColumnDefinition Width="200" />
</Grid.ColumnDefinitions>
<Button Content="Generate" Grid.Row="1" HorizontalAlignment="Left" Name="button1" VerticalAlignment="Top" Height="50" Click="GenerateSerialization" />
<ScrollViewer Name="scrollText" Grid.Column="2"></ScrollViewer>
<sdk:GridSplitter Grid.Row="0" Grid.Column="1" HorizontalAlignment="Center" Name="gridSplitter1" VerticalAlignment="Stretch" />
</Grid>

Sorry... when I think I understand English I see have a lot of road to travel :o)
Check this:
<ScrollViewer Name="scrollText"
HorizontalScrollBarVisibility="Disabled"
Grid.Column="2">
<TextBox TextWrapping="Wrap"
Text="Bla, bla, bla..." />
</ScrollViewer>